Four cavers were reported some 3 hours overdue from their expected return from a trip down Curtain Pot on Malham Moor. The informant had become more concerned due to the onset of a thunderstorm with heavy rain. Whilst CRO were mobilising a rescue response, the informant contacted CRO again to advise that four figures could be seen heading down to his position. A short while later CRO received confirmation that the cavers were all safe and well.